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- /* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- #include <string.h>
- #include <openssl/err.h>
- #include <openssl/rsa.h>
- #include <openssl/pem.h>
- #include <openssl/evp.h>
- #include <openssl/rand.h>
- #include <openssl/opensslv.h>
- #include <openssl/bn.h>
- #include <openssl/dh.h>
- #include <stdlib.h>
- #include <assert.h>
- #include <stdio.h>
- #include <limits.h>
- #include "crypto.h"
- #include "../or/or.h"
- #include "log.h"
- #include "aes.h"
- #if OPENSSL_VERSION_NUMBER < 0x00905000l
- #error "We require openssl >= 0.9.5"
- #elif OPENSSL_VERSION_NUMBER < 0x00906000l
- #define OPENSSL_095
- #endif
- /*
- * Certain functions that return a success code in OpenSSL 0.9.6 return void
- * (and don't indicate errors) in OpenSSL version 0.9.5.
- *
- * [OpenSSL 0.9.5 matters, because it ships with Redhat 6.2.]
- */
- #ifdef OPENSSL_095
- #define RETURN_SSL_OUTCOME(exp) (exp); return 0
- #else
- #define RETURN_SSL_OUTCOME(exp) return !(exp)
- #endif
- struct crypto_pk_env_t
- {
- int type;
- int refs; /* reference counting; so we don't have to copy keys */
- unsigned char *key;
- /* auxiliary data structure(s) used by the underlying crypto library */
- unsigned char *aux;
- };
- struct crypto_cipher_env_t
- {
- int type;
- unsigned char *key;
- unsigned char *iv;
- /* auxiliary data structure(s) used by the underlying crypto library */
- unsigned char *aux;
- };
- /* static INLINE const EVP_CIPHER *
- crypto_cipher_evp_cipher(int type, int enc);
- */
- static INLINE int
- crypto_cipher_iv_length(int type) {
- /*
- printf("%d -> %d IV\n",type, EVP_CIPHER_iv_length(
- crypto_cipher_evp_cipher(type,0)));
- */
- switch(type)
- {
- case CRYPTO_CIPHER_IDENTITY: return 0;
- case CRYPTO_CIPHER_DES: return 8;
- case CRYPTO_CIPHER_RC4: return 16;
- case CRYPTO_CIPHER_3DES: return 8;
- case CRYPTO_CIPHER_AES_CTR: return 0;
- default: assert(0); return -1;
- }
- }
- static INLINE int
- crypto_cipher_key_length(int type) {
- /*
- printf("%d -> %d\n",type, EVP_CIPHER_key_length(
- crypto_cipher_evp_cipher(type,0)));
- */
- switch(type)
- {
- case CRYPTO_CIPHER_IDENTITY: return 0;
- case CRYPTO_CIPHER_DES: return 8;
- case CRYPTO_CIPHER_RC4: return 16;
- case CRYPTO_CIPHER_3DES: return 16;
- case CRYPTO_CIPHER_AES_CTR: return 16;
- default: assert(0); return -1;
- }
- }
- static INLINE const EVP_CIPHER *
- crypto_cipher_evp_cipher(int type, int enc) {
- switch(type)
- {
- case CRYPTO_CIPHER_IDENTITY: return EVP_enc_null();
- case CRYPTO_CIPHER_DES: return EVP_des_ofb();
- case CRYPTO_CIPHER_RC4: return EVP_rc4();
- case CRYPTO_CIPHER_3DES: return EVP_des_ede_ofb();
- default: return NULL;
- }
- }
- static int _crypto_global_initialized = 0;
- int crypto_global_init()
- {
- if (!_crypto_global_initialized) {
- ERR_load_crypto_strings();
- _crypto_global_initialized = 1;
- }
- return 0;
- }
- int crypto_global_cleanup()
- {
- ERR_free_strings();
- return 0;
- }
- crypto_pk_env_t *_crypto_new_pk_env_rsa(RSA *rsa)
- {
- crypto_pk_env_t *env;
- assert(rsa);
- env = (crypto_pk_env_t *)tor_malloc(sizeof(crypto_pk_env_t));
- env->type = CRYPTO_PK_RSA;
- env->refs = 1;
- env->key = (unsigned char*)rsa;
- env->aux = NULL;
- return env;
- }
- RSA *_crypto_pk_env_get_rsa(crypto_pk_env_t *env)
- {
- if (env->type != CRYPTO_PK_RSA)
- return NULL;
- return (RSA*)env->key;
- }
- EVP_PKEY *_crypto_pk_env_get_evp_pkey(crypto_pk_env_t *env)
- {
- RSA *key = NULL;
- EVP_PKEY *pkey = NULL;
- if (env->type != CRYPTO_PK_RSA)
- return NULL;
- assert(env->key);
- if (!(key = RSAPrivateKey_dup((RSA*)env->key)))
- goto error;
- if (!(pkey = EVP_PKEY_new()))
- goto error;
- if (!(EVP_PKEY_assign_RSA(pkey, key)))
- goto error;
- return pkey;
- error:
- if (pkey)
- EVP_PKEY_free(pkey);
- if (key)
- RSA_free(key);
- return NULL;
- }
- crypto_pk_env_t *crypto_new_pk_env(int type)
- {
- RSA *rsa;
- switch(type) {
- case CRYPTO_PK_RSA:
- rsa = RSA_new();
- if (!rsa) return NULL;
- return _crypto_new_pk_env_rsa(rsa);
- default:
- return NULL;
- }
- }
- void crypto_free_pk_env(crypto_pk_env_t *env)
- {
- assert(env);
- if(--env->refs > 0)
- return;
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (env->key)
- RSA_free((RSA *)env->key);
- break;
- default:
- break;
- }
-
- free(env);
- }
- /* Create a new crypto_cipher_env_t for a given onion cipher type, key,
- * iv, and encryption flag (1=encrypt, 0=decrypt). Return the crypto object
- * on success; NULL on failure.
- */
- crypto_cipher_env_t *
- crypto_create_init_cipher(int cipher_type, char *key, char *iv, int encrypt_mode)
- {
- int r;
- crypto_cipher_env_t *crypto = NULL;
- if (! (crypto = crypto_new_cipher_env(cipher_type))) {
- log_fn(LOG_WARN, "Unable to allocate crypto object");
- return NULL;
- }
- if (crypto_cipher_set_key(crypto, key)) {
- log_fn(LOG_WARN, "Unable to set key: %s", crypto_perror());
- goto error;
- }
- if (crypto_cipher_set_iv(crypto, iv)) {
- log_fn(LOG_WARN, "Unable to set iv: %s", crypto_perror());
- goto error;
- }
-
- if (encrypt_mode)
- r = crypto_cipher_encrypt_init_cipher(crypto);
- else
- r = crypto_cipher_decrypt_init_cipher(crypto);
- if (r) {
- log_fn(LOG_WARN, "Unable to initialize cipher: %s", crypto_perror());
- goto error;
- }
- return crypto;
- error:
- if (crypto)
- crypto_free_cipher_env(crypto);
- return NULL;
- }
- crypto_cipher_env_t *crypto_new_cipher_env(int type)
- {
- crypto_cipher_env_t *env;
- int iv_len, key_len;
-
- env = (crypto_cipher_env_t *)tor_malloc(sizeof(crypto_cipher_env_t));
-
- env->type = type;
- env->key = NULL;
- env->iv = NULL;
- env->aux = NULL;
- iv_len = crypto_cipher_iv_length(type);
- key_len = crypto_cipher_key_length(type);
-
- if (type == CRYPTO_CIPHER_AES_CTR) {
- env->aux = (unsigned char *)aes_new_cipher();
- } else if (! crypto_cipher_evp_cipher(type,0))
- /* This is not an openssl cipher */
- goto err;
- else {
- env->aux = (unsigned char *)tor_malloc(sizeof(EVP_CIPHER_CTX));
- EVP_CIPHER_CTX_init((EVP_CIPHER_CTX *)env->aux);
- }
- if(iv_len)
- env->iv = (unsigned char *)tor_malloc(iv_len);
- if(key_len)
- env->key = (unsigned char *)tor_malloc(key_len);
-
- return env;
- err:
- if (env->key)
- free(env->key);
- if (env->iv)
- free(env->iv);
- if (env->aux)
- free(env->aux);
- if (env)
- free(env);
- return NULL;
- }
- void crypto_free_cipher_env(crypto_cipher_env_t *env)
- {
- assert(env);
- if (env->type == CRYPTO_CIPHER_AES_CTR) {
- assert(env->aux);
- aes_free_cipher((aes_cnt_cipher_t*)env->aux);
- env->aux = NULL;
- } else if (crypto_cipher_evp_cipher(env->type,0)) {
- /* This is an openssl cipher */
- assert(env->aux);
- EVP_CIPHER_CTX_cleanup((EVP_CIPHER_CTX *)env->aux);
- }
- if (env->aux)
- free((void *)env->aux);
- if (env->iv)
- free((void *)env->iv);
- if (env->key)
- free((void *)env->key);
- free((void *)env);
- }
- /* public key crypto */
- int crypto_pk_generate_key(crypto_pk_env_t *env)
- {
- assert(env);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (env->key)
- RSA_free((RSA *)env->key);
- env->key = (unsigned char *)RSA_generate_key(1024,65537, NULL, NULL);
- if (!env->key)
- return -1;
- break;
- default:
- return -1;
- }
-
- return 0;
- }
- int crypto_pk_read_private_key_from_file(crypto_pk_env_t *env, FILE *src)
- {
- assert(env && src);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (env->key)
- RSA_free((RSA *)env->key);
- env->key = (unsigned char *)PEM_read_RSAPrivateKey(src, NULL, NULL, NULL);
- if (!env->key)
- return -1;
- break;
- default :
- return -1;
- }
-
- return 0;
- }
- int crypto_pk_read_private_key_from_filename(crypto_pk_env_t *env, const char *keyfile)
- {
- FILE *f_pr;
-
- assert(env && keyfile);
-
- if(strspn(keyfile,CONFIG_LEGAL_FILENAME_CHARACTERS) != strlen(keyfile)) {
- /* filename contains nonlegal characters */
- return -1;
- }
- /* open the keyfile */
- f_pr=fopen(keyfile,"rb");
- if (!f_pr)
- return -1;
-
- /* read the private key */
- if(crypto_pk_read_private_key_from_file(env, f_pr) < 0) {
- log_fn(LOG_WARN,"Error reading private key : %s",crypto_perror());
- fclose(f_pr);
- return -1;
- }
- fclose(f_pr);
-
- /* check the private key */
- switch(crypto_pk_check_key(env)) {
- case 0:
- log_fn(LOG_WARN,"Private key read but is invalid : %s.", crypto_perror());
- return -1;
- case -1:
- log_fn(LOG_WARN,"Private key read but validity checking failed : %s",crypto_perror());
- return -1;
- /* case 1: fall through */
- }
- return 0;
- }
- int crypto_pk_read_public_key_from_file(crypto_pk_env_t *env, FILE *src)
- {
- assert(env && src);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if(env->key)
- RSA_free((RSA *)env->key);
- env->key = (unsigned char *)PEM_read_RSAPublicKey(src, NULL, NULL, NULL);
- if (!env->key)
- return -1;
- break;
- default :
- return -1;
- }
-
- return 0;
- }
- int crypto_pk_write_public_key_to_string(crypto_pk_env_t *env, char **dest, int *len) {
- BUF_MEM *buf;
- BIO *b;
- assert(env && env->key && dest);
- switch(env->type) {
- case CRYPTO_PK_RSA:
- b = BIO_new(BIO_s_mem()); /* Create a memory BIO */
- /* Now you can treat b as if it were a file. Just use the
- * PEM_*_bio_* functions instead of the non-bio variants.
- */
- if(!PEM_write_bio_RSAPublicKey(b, (RSA *)env->key))
- return -1;
- BIO_get_mem_ptr(b, &buf);
- BIO_set_close(b, BIO_NOCLOSE); /* so BIO_free doesn't free buf */
- BIO_free(b);
- *dest = tor_malloc(buf->length+1);
- memcpy(*dest, buf->data, buf->length);
- (*dest)[buf->length] = 0; /* null terminate it */
- *len = buf->length;
- BUF_MEM_free(buf);
- break;
- default:
- return -1;
- }
-
- return 0;
- }
- int crypto_pk_read_public_key_from_string(crypto_pk_env_t *env, const char *src, int len) {
- BIO *b;
- assert(env && src);
- switch(env->type) {
- case CRYPTO_PK_RSA:
- b = BIO_new(BIO_s_mem()); /* Create a memory BIO */
- BIO_write(b, src, len);
- RSA_free((RSA *)env->key);
- env->key = (unsigned char *)PEM_read_bio_RSAPublicKey(b, NULL, NULL, NULL);
- if(!env->key)
- return -1;
- BIO_free(b);
- break;
- default:
- return -1;
- }
-
- return 0;
- }
- int
- crypto_pk_write_private_key_to_filename(crypto_pk_env_t *env,
- const char *fname)
- {
- BIO *bio;
- char *cp;
- long len;
- char *s;
- int r;
- assert(env->type == CRYPTO_PK_RSA);
- if (!(bio = BIO_new(BIO_s_mem())))
- return -1;
- if (PEM_write_bio_RSAPrivateKey(bio, (RSA*)env->key, NULL,NULL,0,NULL,NULL)
- == 0) {
- BIO_free(bio);
- return -1;
- }
- len = BIO_get_mem_data(bio, &cp);
- s = tor_malloc(len+1);
- strncpy(s, cp, len);
- s[len] = '\0';
- r = write_str_to_file(fname, s);
- BIO_free(bio);
- free(s);
- return r;
- }
- int crypto_pk_write_private_key_to_file(crypto_pk_env_t *env, FILE *dest)
- {
- assert(env && dest);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (!env->key)
- return -1;
- if (PEM_write_RSAPrivateKey(dest, (RSA *)env->key, NULL, NULL, 0,0, NULL) == 0)
- return -1;
- break;
- default :
- return -1;
- }
-
- return 0;
- }
- int crypto_pk_write_public_key_to_file(crypto_pk_env_t *env, FILE *dest)
- {
- assert(env && dest);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (!env->key)
- return -1;
- if (PEM_write_RSAPublicKey(dest, (RSA *)env->key) == 0)
- return -1;
- break;
- default :
- return -1;
- }
-
- return 0;
- }
- int crypto_pk_check_key(crypto_pk_env_t *env)
- {
- assert(env);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- return RSA_check_key((RSA *)env->key);
- default:
- return -1;
- }
- }
- int crypto_pk_cmp_keys(crypto_pk_env_t *a, crypto_pk_env_t *b) {
- int result;
-
- if (!a || !b)
- return -1;
-
- if (!a->key || !b->key)
- return -1;
-
- if (a->type != b->type)
- return -1;
-
- switch(a->type) {
- case CRYPTO_PK_RSA:
- assert(((RSA *)a->key)->n && ((RSA *)a->key)->e && ((RSA *)b->key)->n && ((RSA *)b->key)->e);
- result = BN_cmp(((RSA *)a->key)->n, ((RSA *)b->key)->n);
- if (result)
- return result;
- return BN_cmp(((RSA *)a->key)->e, ((RSA *)b->key)->e);
- default:
- return -1;
- }
- }
- int crypto_pk_keysize(crypto_pk_env_t *env)
- {
- assert(env && env->key);
-
- return RSA_size((RSA *)env->key);
- }
- crypto_pk_env_t *crypto_pk_dup_key(crypto_pk_env_t *env) {
- assert(env && env->key);
- switch(env->type) {
- case CRYPTO_PK_RSA:
- env->refs++;
- break;
- default:
- return NULL;
- }
-
- return env;
- }
- int crypto_pk_public_encrypt(crypto_pk_env_t *env, unsigned char *from, int fromlen, unsigned char *to, int padding)
- {
- assert(env && from && to);
-
- switch(env->type) {
- case CRYPTO_PK_RSA:
- return RSA_public_encrypt(fromlen, from, to, (RSA *)env->key, padding);
- default:
- return -1;
- }
- }
- int crypto_pk_private_decrypt(crypto_pk_env_t *env, unsigned char *from, int fromlen, unsigned char *to, int padding)
- {
- assert(env && from && to);
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (!(((RSA*)env->key)->p))
- return -1;
- return RSA_private_decrypt(fromlen, from, to, (RSA *)env->key, padding);
- default:
- return -1;
- }
- }
- int crypto_pk_public_checksig(crypto_pk_env_t *env, unsigned char *from, int fromlen, unsigned char *to)
- {
- assert(env && from && to);
- switch(env->type) {
- case CRYPTO_PK_RSA:
- return RSA_public_decrypt(fromlen, from, to, (RSA *)env->key,
- RSA_PKCS1_PADDING);
- default:
- return -1;
- }
- }
- int crypto_pk_private_sign(crypto_pk_env_t *env, unsigned char *from, int fromlen, unsigned char *to)
- {
- assert(env && from && to);
- switch(env->type) {
- case CRYPTO_PK_RSA:
- if (!(((RSA*)env->key)->p))
- return -1;
- return RSA_private_encrypt(fromlen, from, to, (RSA *)env->key,
- RSA_PKCS1_PADDING);
- default:
- return -1;
- }
- }
- int
- crypto_pk_get_fingerprint(crypto_pk_env_t *pk, char *fp_out)
- {
- unsigned char *buf, *bufp;
- unsigned char digest[20];
- int len;
- int i;
- assert(pk->type == CRYPTO_PK_RSA);
- len = i2d_RSAPublicKey((RSA*)pk->key, NULL);
- if (len < 0)
- return -1;
- if (len<FINGERPRINT_LEN+1) len = FINGERPRINT_LEN+1;
- buf = bufp = tor_malloc(len+1);
- len = i2d_RSAPublicKey((RSA*)pk->key, &bufp);
- if (len < 0) {
- free(buf);
- return -1;
- }
- if (crypto_SHA_digest(buf, len, digest) < 0) {
- free(buf);
- return -1;
- }
- bufp = buf;
- for (i = 0; i < 20; ++i) {
- sprintf(bufp,"%02X",digest[i]);
- bufp += 2;
- if (i%2 && i != 19) {
- *bufp++ = ' ';
- }
- }
- *bufp = '\0';
- assert(strlen(buf) == FINGERPRINT_LEN);
- assert(crypto_pk_check_fingerprint_syntax(buf));
- strcpy(fp_out, buf);
- free(buf);
- return 0;
- }
- int
- crypto_pk_check_fingerprint_syntax(const char *s)
- {
- int i;
- for (i = 0; i < FINGERPRINT_LEN; ++i) {
- if ((i%5) == 4) {
- if (!isspace(s[i])) return 0;
- } else {
- if (!isxdigit(s[i])) return 0;
- }
- }
- if (s[FINGERPRINT_LEN]) return 0;
- return 1;
- }
- /* symmetric crypto */
- int crypto_cipher_generate_key(crypto_cipher_env_t *env)
- {
- int key_len;
- assert(env);
- key_len = crypto_cipher_key_length(env->type);
- if (key_len > 0)
- return crypto_rand(key_len, env->key);
- else if (key_len == 0)
- return 0;
- else
- return -1;
- }
- int crypto_cipher_set_iv(crypto_cipher_env_t *env, unsigned char *iv)
- {
- int iv_len;
- assert(env && iv);
-
- iv_len = crypto_cipher_iv_length(env->type);
- if (!iv_len)
- return 0;
- if (!env->iv)
- return -1;
- memcpy((void*)env->iv, (void*)iv, iv_len);
-
- return 0;
- }
- int crypto_cipher_set_key(crypto_cipher_env_t *env, unsigned char *key)
- {
- int key_len;
- assert(env && key);
- key_len = crypto_cipher_key_length(env->type);
- if (!key_len)
- return 0;
- if (!env->key)
- return -1;
- memcpy((void*)env->key, (void*)key, key_len);
-
- return 0;
- }
- unsigned char *crypto_cipher_get_key(crypto_cipher_env_t *env)
- {
- return env->key;
- }
- int crypto_cipher_encrypt_init_cipher(crypto_cipher_env_t *env)
- {
- assert(env);
-
- if (crypto_cipher_evp_cipher(env->type, 1)) {
- RETURN_SSL_OUTCOME(EVP_EncryptInit((EVP_CIPHER_CTX *)env->aux,
- crypto_cipher_evp_cipher(env->type, 1),
- env->key, env->iv));
- } else if (env->type == CRYPTO_CIPHER_AES_CTR) {
- aes_set_key((aes_cnt_cipher_t*)env->aux, env->key, 128);
- return 0;
- } else {
- return -1;
- }
- }
- int crypto_cipher_decrypt_init_cipher(crypto_cipher_env_t *env)
- {
- assert(env);
- if (crypto_cipher_evp_cipher(env->type, 0)) {
- RETURN_SSL_OUTCOME(EVP_EncryptInit((EVP_CIPHER_CTX *)env->aux,
- crypto_cipher_evp_cipher(env->type, 0),
- env->key, env->iv));
- } else if (env->type == CRYPTO_CIPHER_AES_CTR) {
- aes_set_key((aes_cnt_cipher_t*)env->aux, env->key, 128);
- return 0;
- } else {
- return -1;
- }
- }
- int crypto_cipher_encrypt(crypto_cipher_env_t *env, unsigned char *from, unsigned int fromlen, unsigned char *to)
- {
- int tolen;
-
- assert(env && from && to);
-
- if (env->type == CRYPTO_CIPHER_AES_CTR) {
- aes_crypt((aes_cnt_cipher_t*)env->aux, from, fromlen, to);
- return 0;
- } else {
- RETURN_SSL_OUTCOME(EVP_EncryptUpdate((EVP_CIPHER_CTX *)env->aux, to, &tolen, from, fromlen));
- }
- }
- int crypto_cipher_decrypt(crypto_cipher_env_t *env, unsigned char *from, unsigned int fromlen, unsigned char *to)
- {
- int tolen;
-
- assert(env && from && to);
- if (env->type == CRYPTO_CIPHER_AES_CTR) {
- aes_crypt((aes_cnt_cipher_t*)env->aux, from, fromlen, to);
- return 0;
- } else {
- RETURN_SSL_OUTCOME(EVP_DecryptUpdate((EVP_CIPHER_CTX *)env->aux, to, &tolen, from, fromlen));
- }
- }
- int
- crypto_cipher_advance(crypto_cipher_env_t *env, long delta)
- {
- if (env->type == CRYPTO_CIPHER_AES_CTR) {
- aes_adjust_counter((aes_cnt_cipher_t*)env->aux, delta);
- return 0;
- } else {
- return -1;
- }
- }
- /* SHA-1 */
- int crypto_SHA_digest(const unsigned char *m, int len, unsigned char *digest)
- {
- assert(m && digest);
- return (SHA1(m,len,digest) == NULL);
- }
- static BIGNUM *dh_param_p = NULL;
- static BIGNUM *dh_param_g = NULL;
- static void init_dh_param() {
- BIGNUM *p, *g;
- int r;
- if (dh_param_p && dh_param_g)
- return;
-
- p = BN_new();
- g = BN_new();
- assert(p && g);
- #if 0
- /* This is from draft-ietf-ipsec-ike-modp-groups-05.txt. It's a safe
- prime, and supposedly it equals:
- 2^1536 - 2^1472 - 1 + 2^64 * { [2^1406 pi] + 741804 }
- */
- r = BN_hex2bn(&p,
- "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
- "29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
- "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
- "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
- "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
- "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
- "83655D23DCA3AD961C62F356208552BB9ED529077096966D"
- "670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF");
- #endif
- /* This is from rfc2409, section 6.2. It's a safe prime, and
- supposedly it equals:
- 2^1024 - 2^960 - 1 + 2^64 * { [2^894 pi] + 129093 }.
- */
- /* See also rfc 3536 */
- r = BN_hex2bn(&p,
- "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08"
- "8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B"
- "302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9"
- "A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6"
- "49286651ECE65381FFFFFFFFFFFFFFFF");
- assert(r);
- r = BN_set_word(g, 2);
- assert(r);
- dh_param_p = p;
- dh_param_g = g;
- }
- crypto_dh_env_t *crypto_dh_new()
- {
- crypto_dh_env_t *res = NULL;
- if (!dh_param_p)
- init_dh_param();
-
- res = tor_malloc(sizeof(crypto_dh_env_t));
- res->dh = NULL;
- if (!(res->dh = DH_new()))
- goto err;
- if (!(res->dh->p = BN_dup(dh_param_p)))
- goto err;
- if (!(res->dh->g = BN_dup(dh_param_g)))
- goto err;
- return res;
- err:
- if (res && res->dh) DH_free(res->dh); /* frees p and g too */
- if (res) free(res);
- return NULL;
- }
- int crypto_dh_get_bytes(crypto_dh_env_t *dh)
- {
- assert(dh);
- return DH_size(dh->dh);
- }
- int crypto_dh_get_public(crypto_dh_env_t *dh, char *pubkey, int pubkey_len)
- {
- int bytes;
- assert(dh);
- if (!DH_generate_key(dh->dh))
- return -1;
-
- assert(dh->dh->pub_key);
- bytes = BN_num_bytes(dh->dh->pub_key);
- if (pubkey_len < bytes)
- return -1;
-
- memset(pubkey, 0, pubkey_len);
- BN_bn2bin(dh->dh->pub_key, pubkey+(pubkey_len-bytes));
- return 0;
- }
- #undef MIN
- #define MIN(a,b) ((a)<(b)?(a):(b))
- int crypto_dh_compute_secret(crypto_dh_env_t *dh,
- char *pubkey, int pubkey_len,
- char *secret_out, int secret_bytes_out)
- {
- unsigned char hash[20];
- unsigned char *secret_tmp = NULL;
- BIGNUM *pubkey_bn = NULL;
- int secret_len;
- int i;
- assert(dh);
- assert(secret_bytes_out/20 <= 255);
- if (!(pubkey_bn = BN_bin2bn(pubkey, pubkey_len, NULL)))
- goto error;
- secret_tmp = tor_malloc(crypto_dh_get_bytes(dh)+1);
- secret_len = DH_compute_key(secret_tmp, pubkey_bn, dh->dh);
- for (i = 0; i < secret_bytes_out; i += 20) {
- secret_tmp[secret_len] = (unsigned char) i/20;
- if (crypto_SHA_digest(secret_tmp, secret_len+1, hash))
- goto error;
- memcpy(secret_out+i, hash, MIN(20, secret_bytes_out-i));
- }
- secret_len = secret_bytes_out;
- goto done;
- error:
- secret_len = -1;
- done:
- if (pubkey_bn)
- BN_free(pubkey_bn);
- if (secret_tmp)
- free(secret_tmp);
- return secret_len;
- }
- void crypto_dh_free(crypto_dh_env_t *dh)
- {
- assert(dh && dh->dh);
- DH_free(dh->dh);
- free(dh);
- }
- /* random numbers */
- int crypto_seed_rng()
- {
- static char *filenames[] = {
- "/dev/srandom", "/dev/urandom", "/dev/random", NULL
- };
- int i, n;
- char buf[21];
- FILE *f;
-
- for (i = 0; filenames[i]; ++i) {
- f = fopen(filenames[i], "rb");
- if (!f) continue;
- log_fn(LOG_INFO, "Seeding RNG from %s", filenames[i]);
- n = fread(buf, 1, 20, f);
- fclose(f);
- if (n != 20) {
- log_fn(LOG_WARN, "Error reading from entropy source");
- return -1;
- }
- RAND_seed(buf, 20);
- return 0;
- }
- log_fn(LOG_WARN, "Cannot seed RNG -- no entropy source found.");
- return -1;
- }
- int crypto_rand(unsigned int n, unsigned char *to)
- {
- assert(to);
- return (RAND_bytes(to, n) != 1);
- }
- void crypto_pseudo_rand(unsigned int n, unsigned char *to)
- {
- assert(to);
- if (RAND_pseudo_bytes(to, n) == -1) {
- log_fn(LOG_ERR, "RAND_pseudo_bytes failed unexpectedly.");
- exit(1);
- }
- }
- /* return a pseudo random number between 0 and max-1 */
- int crypto_pseudo_rand_int(unsigned int max) {
- unsigned int val;
- unsigned int cutoff;
- assert(max < UINT_MAX);
- assert(max > 0); /* don't div by 0 */
- /* We ignore any values that are >= 'cutoff,' to avoid biasing the
- * distribution with clipping at the upper end of unsigned int's
- * range.
- */
- cutoff = UINT_MAX - (UINT_MAX%max);
- while(1) {
- crypto_pseudo_rand(sizeof(val), (unsigned char*) &val);
- if (val < cutoff)
- return val % max;
- }
- }
- /* errors */
- char *crypto_perror()
- {
- return (char *)ERR_reason_error_string(ERR_get_error());
- }
- int
- base64_encode(char *dest, int destlen, const char *src, int srclen)
- {
- EVP_ENCODE_CTX ctx;
- int len, ret;
-
- /* 48 bytes of input -> 64 bytes of output plus newline.
- Plus one more byte, in case I'm wrong.
- */
- if (destlen < ((srclen/48)+1)*66)
- return -1;
- EVP_EncodeInit(&ctx);
- EVP_EncodeUpdate(&ctx, dest, &len, (char*) src, srclen);
- EVP_EncodeFinal(&ctx, dest+len, &ret);
- ret += len;
- return ret;
- }
- int
- base64_decode(char *dest, int destlen, const char *src, int srclen)
- {
- EVP_ENCODE_CTX ctx;
- int len, ret;
- /* 64 bytes of input -> *up to* 48 bytes of output.
- Plus one more byte, in caes I'm wrong.
- */
- if (destlen < ((srclen/64)+1)*49)
- return -1;
- EVP_DecodeInit(&ctx);
- EVP_DecodeUpdate(&ctx, dest, &len, (char*) src, srclen);
- EVP_DecodeFinal(&ctx, dest, &ret);
- ret += len;
- return ret;
- }
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